Many people refer to Apache Hadoop as their system of choice for big data management but few actually use just Apache Hadoop. Hadoop has become a proxy for a much larger system which has HDFS storage at its core. The Apache Hadoop based "big data stack" has changed dramatically over the past 24 months and will chance even more over the next 24 months. This talk talks about trends in the evolution of the Hadoop stack, change in architecture and changes in the kinds of use cases that are supported. It will also talk about the role of interoperability and cohesion in the Apache Hadoop stack and the role of Apache Bigtop in this regard.